Tension releasing device for sewing machines



Jan. 8, 1952 E. P. TURNER 2,532,211

I TENSION RELEASING DEVICE FOR SEWING MACHINES 1 Filed May 20, 1950 2 SHEETSSI-IEET 1 Edgar Zbmer Wane,

255 V x wy Jan. 8-, 1952 TURNER 2,582,211

TENSION RELEASING DEVICE FOR SEWING MACHINES Filed May 20, 1950 I 2 SHEETS-SHEET 2 I I Jnvenfoz Egar P Tamer Wiinm $85 I v p W aifio zney Patented Jan. 8, 1952 TENSION RELEASING DEVICE FOR SEWING MACHINES Edgar P. Turner, Fanwood, N. J assignor to The Singer Manufacturing Company, Elizabeth, 7 N. J., a corporation of New Jersey Application May :20, 1950, Serial No. 163,199

This invention. relates to sewing machines of the type employing tensioning means for the -sew-' ing thread and has for an object to provide an improved device for rendering such tensioning means temporarily ineffective for tensioning the thread.

The further object of the present invention is to provide a sewing machine with a thread tension.;device having a tension releasing means" which is so design-ed that it may be conveniently operated froma position remote from the sewing machine proper.

A still further object of the present invention isto provide an improved thread tension con-' trolling means for an organized pantographequipped embroidering machine of the type Which is adapted-for placing monograms on sheets, towels, garments and the like goods. 1.

-With the above and other objects in view, as will hereinafter appear, the invention comprises thedevices, combinations and arrangements of parts hereinafter setforth and illustrated in the accompanying drawings of a preferred embodiment of the invention from which the several features of the invention andthe advantages attained thereby will be, readily understood by thosev skilled in the art.

. In the drawings:

Fig. l represents a perspective view of an embroidering machine in which the present invention is employed.

Fig. 2 represents a wiring diagram for the S0181 noid which operates the present tensioning device.

Fig. 3 represents a top plan view of a pantograph unit which is employed in conjunction with the present sewing machine.

Fig. 4 represents a fragmentary frontelevational view of a sewing machine head on which is mounted the present tensioning device.

Fig. 5 represents, on an enlarged scale, a sectional View taken substantially along the line 5--5 of Fig. 4; which view illustrates the tension 3 Claims. (01.112-254) 2 ployed on the present panograph unit illustrated in Figs. 1 and 3.

Referring to the drawings, the present invention may beemployed with an embroidery mechanism having a zigzag type sewing machine l0 and. a manually controlled pantograph mechanism ll of which one end portion carries an embroidery hoop 12 for presenting beneath the vibratory needle [3 of the sewing machine the Work to be monogrammed. The other end portion of the pantograph mechanism carries a stylus, generally designated by the. numeral I4, which the operator employs for tracing a monogram stencil or pattern which may be presented beneath the pantograph. The movements of the embroidery hoop are directly controlled by the operator through the pantograph and thus the monogram formed in the work by the sewing machine corresponds to the stencil or pattern. For a more detailed description of a related pantograph and sewing machine unit, reference may be hadv to the U. S. patent of Corrall, No. 1,328,821, January 2'7, 1920.

A knee-shift lever I5 is provided for enablingthe operatorto vary the amplitude of lateral needle vibration so that the width of zigzag seams may be altered during the stitching operation to the endthat the monogram outline may be of divers widths.

Referring particularly to Fig. 1, the present invention is incorporated in a table i6 having a substantially flat upper surface I! which is provided at one end portion with a conventional sewing macine cut-out l8 for receiving therein the above noted zigzag sewing machine generally designated by the numeral Ill.

Mounted directly beneath the table top and upon a shelf I9 carried by the table legs 20, 20 is a horizontally disposed; pantograph-supporting apron 2| which extends outwardly from beneath the table top in order to expose the stylus-supporting end of the pantograph unit. This stylussupporting end of the pantograph mechanism is carried directly upon the outwardly protruding apron 2| while the other end portion thereof is carried by the shelf 9 at a location beneath the table level and in vertical alignment with an opening 22 formed within the table surface. An arm 23 extends upwardly from the pantograph and through the table opening 22 and is provided with a horizontal limb 24 which extends over the table so as to support the embroidery hoop [2 directly over the sewing machine throat-plate and beneath the needle-bar mechanism.

The upper surface 25 of the protruding apron 3 may be formed from a fiat piece of transparent material directly beneath which, and in a rectangular pocket 26 formed in the apron, a pattern or stencil sheet may be positioned. The stylus head l4 provided on the outwardly protruding end portion of the pantograph may be tracked about a given pattern carried in the apron pocket 26 so as to efiect a corresponding movement of the embroidery hoop E2 to the end that the sewing machine will produce a monogram of predetermined shape.

As hereinabove noted, the present apparatus includes a sewing machine it! of the so-called zigzag type which comprisesa flat bed 21 affording a work-support and from-one end of which rises a hollow standard 28 of a bracket-arm 29 over-hanging the bed-plate and terminating in a needle-bar carrying head 33.

The present sewing machine is of a conventional zigzag type which includes a vertically reciprocatory and laterally vibratory needle I3 which is adapted to form the zigzag stitches in work material. Machines of this type employ means for varying the amplitude of lateral needle vibration from zero to a maximum amount and in the machine illustrated there is provided a lever arm 3! for this purpose. For a more complete description of this zigzag type sewing machine with its accompanying vibratory needle-bar control, reference may be had to the U. S. patent of Eames, No. 2,005,673, June 18, 1935.

The above noted pantograph device ll comprises a manually movable arm 32 which is pivotally secured by means of pins 33, 33 to a pair of link arms 34 and 35, each of which latter elements are, in turn, pivotally secured to a third link arm 36 by means of pins 31, 31 thereby to form a conventional'pantograph structure. Embracing the link arm 34 is a collar member 38 which is pivotally mounted upon the apron by means of a pin 39. From this it will be understood that movement of the main arm 32 will function to shift the various pantograph links relative to each other and the entire unit will pivot about the pin 39 in the usual fashion.

Attached to the above described mainportions of'the pantograph mechanism is an auxiliary mechanism whichincludes a pair of parallel arms 40 and 4|, each of which is pivotallysecured at its one end portion to an arm 42 as by means-of appropriate pins. The other end portion of each of the arms 43 and 4| is-pivotally secured to one limb of a bell-crank lever 43 by means of an appropriate pin element. The other limb of the bell-crank lever 43 is pivotally secured to the end portions of each of a second pair of parallel arms designated by the numerals 44 and45, which arms are pivotally secured at their other end portions by means of pins 46, 46 to a block 4-! which is fixedly secured to the shelf member 19.

The free end portion of the arm 42 is provided with a suitable clamping mechanism 48 for the purpose of adjustably carrying the above noted upstanding arm 23 which projects upwardly through the table aperture 22 so as to support upon its upper end portion the above noted workholding member 12.

From the above, it will be readily appreciated that as the stylus head M, which is carried by the free end portion of the pantograph H, is tracked about the lines of a pattern drawing disposed within the apron pocket 26, the hoop element [2 will faithfully reproduce the motions ofthe stylus head all in a conventional manner.

- The present stylus head has incorporated therein means for giving the operator a visual indication of the amplitude of lateral needle vibration. Briefly stated, this means produces upon a, pattern drawing a light spot in the form of an elongated beam, the length of which is made to vary in accordance with the variations in the needle throw amplitude. Thus, the operator at all times will be advised visually as to the width of the monogram which the sewing machine is producing upon a work-piece. The details of the above described embroidering machine, including the "zigzag sewing machine head and the pantograph, along with the pantograph-supporting table, do not form a part of the present invention and thus a detailed explanation of this device is not contained herein. For a more complete: disclosure of the present embroidering apparatus, reference may be had to a co-pending United States patent application of Turner and Sailer Serial No. 160,486, filed May 6, 1950, entitled Design Reproducing Apparatus and Stylus-Unit Therefor.

As hereinabove noted, the present embroidering device is adapted to produce on a piece of work material various monograms which the operator produces one by one, and in most cases these monograms are entirely unconnected with each other. Thus, it. is necessary for the operator to shift the work relative to the sewing machine before making successive monograms. Those skilled in the art will readily appreciate that the work material cannot be moved relative to the sewing machine head without firstreleasing the needle-thread tension in order to prevent the moving-work from breaking the needle thread or perhaps the needle itself. The present invention contemplates the provision of means whereby the operator may readily release the needlethread tension before shifting the work. Figs. 4, 5,6 and 7 particularly illustrate the present tensioningmeans. Referring first to Figs. 4 and 5, the sewing machine head 30 employs the usual type ofreciprocatoryneedle [3 as well as a conventional reciprocatory needle-thread take-up arm 49.. The sewing machine head is formed with an ap'erture50 which-receives a hollow cylindrical shank 5| of a needle-thread tension device, which shank may be suitably secured within the aperture so as to fix the tension device-in workingposition on the sewing machinehead.

The shank 5| is of hollow cylindrical form-and hasan inner end wall 52 formed with a central aperture 53 through which passes the reduced and threaded inner end portion of a hollow stem 54 which is tightly fixed within the base portion itself. Surrounding the stem 54 are the opposed tension disks 55 and 56, of which the disk 55 rests against the rim 5'! of the hollow shank member 5|. The outer end portion of the stem 54 is formed with a longitudinal diametrical. slot 58 through which passes a diameter bar 59 crossing the central stem-embracing aperture 60 in a shallowba'se cup 6| which is pressed against the tension disk by a beehive spring 62.

The spring 62 is engaged at'its outer 'end by a ring-shaped member 63 preferably in the form of-a washer formed with a' diameter bar 64 having a forwardly extending stem portion 65 disposed in the slot 58 of the stem. The washer 63 is engaged or backed by a dial nut 66 having an-outwardly flaring conical skirt 6'! of which the rim is slightly smaller'than and is received within the rim of the base cup 6|. The skirt 61 is 'preferablyformed integral with and nonassaarn of the nut and it overhangs and encloses'the-r major portion of the beehive spring 62. The nut 66. is preferably screw threaded on the split stem;

54. and hasan .innerrcylindrical rece'ssportion 68 which receives the .washer 63 and into which cylindrical recess portion projects a stop-:pin 69 fixed in the nut '66. (See Fig. 7.) The stop-pin 69 normally works in a clearance groove in the washer 63 and this clearancegroove is inter-,

mum to max-imumrequirement; the strength and stiffness of the spring and'the pitch of the screw threads on the stemfor the nut being proportioned to attain this result. The washer 63 thusconstitutes a stop between the nut 66 and the spring 62, which stop is'engaged by, the pin 69 of the nut.

There is disposed within the hollow stem 54' the usual presser control tension release pin 12 which engages thediameter bar 59 of the base cup and relieves the tension disks of the pressure, of the spring when the usual presser-bar foot,

not herein shown, is lifted.

Surrounding the stem 54 within the shank 5| is a check-spring 13 of which one end extends through a slot 14 in the end wall of the shank member and isformed with a loop 15 to anchor it to the shank 5|. The other end of the checkspring extends outwardly through a slot 16 in the rim of the shank 5| and is'formed with the usual thread-engaging loop 11.

The base cup 6| is preferably rovided with an index mark and the skirt 61 of the nut 66 is graduated so that when the user has the tension correctly adjusted for a certain grade of work, the. figureon the dial may be noted and the desired tension immediately restored whenever desired.= I

For a more detailed explanation and description of thepresent tension device, reference may be had to the, U. S. patent of D. H. Chason, No. 1,820,119, August 25, 1931.

As may be particularlynoted ineFig. 4, the needle-thread, generally designated by the numeral I8, is led from a source of supply, not herein shown, through a stationary loop member 19 carried by the sewing machine head and then to the, tension device ,in the usual fashion. More specifically, the thread 18 is led between the tension disks 55 and 56 and about the stem 54 and then up through the wire loop before being led downwardly to a second stationary arm 80 carried by the sewing machine head. From this latter arm '89 the thread is led directly to the usual take-up member 49 whichprojects through a slot 8| provided in the sewing machine'head'. Thereafter, the thread is directed downwardly through a third stationary loop member 82 and then to a fourth member 83 carried by the needlebar 84 after which the thread is directed to the needle |3, all in a conventional fashion. Means,

not herein shown, are provided in the sewing 6 on the needle-thread. Figs. 4, 5, 6 and 8 particularly illustrate this improved device. Briefly stated, the present deyice comprises a solenoid which is carried by the sewing machine head:

and which is adapted to be actuated so as toi release device while operating the stylus head portion .of the pantograph. The present solenoid device is generally designated by the numeral 85 and comprises a bracket 86 which is secured directly to the sewing ma chine head as by means of screws 81, 81. This bracket is provided with an ear portion 88 which has suitably secured thereto, as by means of solder, a cylindrical shaped casing 89 which houses the solenoid proper. As may be best seen from Fig. 5, the solenoid includes a wire-wound coil '98 and an armature or tension release pin 9| which is slidingly disposed within a, cylindrical aperture 92 provided lengthwise of the wire coil. More" specifically, the solenoid coil 9|] is carried within. a cylindrical casing 93 which is suitably secured to a disk member 94 which, in turn, is secured to the ear portion 88 of the bracket 86 as by meansof soldering. The solenoid armature pin 9| is suitably mount-* ed within an aperture 95 formed both in the ear portion 88 of the bracket 86 as well as in the disk member 94. The one end portion of the armature'pin 9| is'provided with a reduced shank, the distal end portion of which is threaded as at 96. Mounted on this reduced shank of the arma ture pin is a stop disk 91 which is held'against' the armature pin shoulder'98 by means of a nut 99 positioned over the threaded end portion of the armature shank. The other end portion of the armature pin is pointed, as at I00, while an intermediate portion of the pin is provided with a stop shoulder |0|.

Referring particularly to Figs. 4 and 5, it is to be noted that the bracket 86, carrying the sole-' noid 85, is so disposed relative to the above described tension device that its armature pin 9| is located at right angles to the stem 54 of the tension device. Furthermore, the pointed end portion 169 of the armature pin is normally disposed between the outer flange portionsof the twotension disks 55 and 56. As may be noted in Fig. 5, the beehive spring 62 of the tension unit is suflicientlystrong normally to force the tension disks together and thereby preclude the entrance of the armature pin therebetween. However,- whenever the solenoid is electrically energized, the armature pin I00 will be forced toward the tension device, thereby to open the two tension disks and release the needle thread. Fig. 6 illustrates the tension disks as being forced open by means of the armature pin I09, which, when the solenoid is energized, is forced toward the shank 54. From this figure, it will be observed that the disk 91, carried by the right-hand end portion of the solenoid armature pin, acts as a stop which prevents the armature pin from moving beyond a predetermined amplitude.

Referring particularly to Fig. 2, there is shown a Wiring diagram which illustrates the solenoid coil and the shiftable armature pin 9|. This solenoid coil is adapted to be connected to a suitable source of electrical energy, such as 90 volts D. C., by means of suitable conductors I02 and 1.03. .A switch? I 0.4a is connected; between. one leg of theelectrical-supply:source illSoand the solenoid coil in a conventional tashiondorxthe purpose of selectively energizing; and. de-energizing. the solenoid.

vAsehereinaliove noted, the switch lMr'ior enersizing the. solenoid. .is,-. in the: present invention, carried in the stylus head of i-the pantograph unit. in a; manner. as may bebestobserved from her slidingly mounted within a:boss= H2 provided 7 inthe stylus headcover.

The. mainactuating pin 1 i0 of;the. switch is; in a conventional fashion, designed to be spring biasedupwardly so that; the solenoid is normally de-energized. Fromthis, it will be appreciated that as soon as theoperator depresses; the pin III the switchactuating pin H0. will be likewise depressed to the end that the switch-I64 will beclosed for thepurpose of connecting'the solenoid coil, 90 to the sourcetof electricalenergy. As soon as the solenoidis thus energized, the armature pin- 9 I will beiorced: outwardly so, that itspointed end portion It!!! will: project between the-disk elements -55 and 56 ofthe tension unit to the end that the. tension will. be, removed: from the needle thread. As hereinahove pointed out.

pin- Ill may be releasedsot-hat the solenoid will.

be de-energized tow the end. that the .tensiondevice will again exert a, proper; pressure upon the needle thread.

.Having thusset' forththenature of thei-nven tion, what I claim herein is:

1. A thread-tension device for sewing machines comprising a pair of thread-engaging elements,

spring means'forxnormallybiasing said threadengaging elements together so as to apply-a tension upon a thread trained between such elements, -an .electrflcatsoienoid including -.a.coil and an armatureishiftabie lengthwise within-saidxcoil, said armature -;being .disposed adjacent said thread-engaging.elementsaandr being: adapted to be. forced; to move lendwise of itself in: opposition totthe action .of said'zspring means: in. response to the energization of. saidsolenoid thereby to relieve the. pressure. between said threadeengaging elements, and a switch-connected to said solenoid and adapted to'xbe connected to'a source of. electrical energy so as: to :be capableof selectively energizing and. de-energizing said solenoid.

.2. 1A thread-tension device'for sewing machines comprisinga pair ofthrea'd-engaging elements, spring meansfonnormally .biasing saidthreadengaging elementstogether thereby toapplya tension upon a thread trained between such elements, an electrical-solenoid including a coil and an armature shiftable :within said coil, said armarture being disposed adjacent said thread-engaging elements so as to be shiftable directly therebetweenin oppositionto the action of said spring means whenever said solenoid is energized and a-switch. connected-to said solenoid and adapted to be connected tea-source of electricalenergy so as to be capable of selectively energizing and de-energizing said solenoid.

.3. In-a sewing machine tension device, ashank, a pair of apertured thread-engaging disks slidably mounted upon and lengthwise of saidshank,

a tension-release pin shiftably mounted-within and lengthwise of said shank, a springsurrounding said shank'for biasingsaid-disks together and for biasing said tensionerelease pin in a direction lengthwise of said shank, an electrical-solenoid including a coil and an armature shiftably mounted within said coil,-said armature being disposed substantially at:right angles tothe-longit-udinal axis of said shankand in-alignment wit the'plane of separation between said disks-so that whenever the coil is energized the armature will be shifted lengthwise of itself and between said disks, and a switch connected with said coil and adapted to: be connected to a sourceof electrical energy so as to be capable of selectively energizingand de-energizingsaid coil.

EDGAR Pl TURNER.

REFERENCES CITED 'The following referencesare of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 658,016 Lei-lich Sept-l8, 1900 1 ,820,119 Chason Aug. 25, 1931 2,064,881 Bowman Dec. 22, 1936 2 ,264,779 Tillett Dec. 2, 1941 

